He added that it is too early to know if other energy resources such as shale gas will be able to develop at a fast enough pace to replace oil and gas. (cnbc.com)
Hydrogen does n`t appear in nature as a fuel; it has to be refined from or manufactured from other energy resources (such as fossil fuels, nuclear, wind or solar). (dotearth.blogs.nytimes.com)
As coal loses favor to natural gas and other alternatives, utilities will retire a significant portion of their coal fleet and invest substantially in other energy resources around the... (aceee.org)